Long-term X-ray variability and state transition of GX 339–4

Kong, Albert; Charles, P. A.; Kuulkers, E.; Kitamoto, Shunji

doi:10.1046/j.1365-8711.2002.05022.x

Cited by 27 publications

(34 citation statements)

References 58 publications

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“…Notice A is approximately at the same flux as the hard X-ray peak before the hard-to-soft state transition (see Kong et al 2002). Notice that the HEXTE peak rates corresponding to A, B, and C correlate with the ASM peak rates of these outbursts, and the peaks in the HEXTE band lead those in the ASM band.…”

Section: Correlation Between the Luminosity Of The Hard-to-softmentioning

confidence: 88%

Peak Luminosities of the Hard States of GX 339‐4: Implications for the Accretion Geometry, Disk Mass, and Black Hole Mass

Lamb

Fender

et al. 2007

ApJ

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We have analyzed observations of the black hole transient GX 339-4 made with the Rossi X-ray Timing Explorer (RXTE ) and the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory (CGRO). We have found a nearly linear relation between the peak flux during the low/hard (LH ) state that occurs at the beginning of an outburst and the time since the flux peak of the latest LH state identified in the previous outburst. Assuming that the rate at which mass accumulates in the accretion disk between these peaks is constant and that any mass that remains in the disk after an outburst has a negligible effect on the next outburst, this nearly linear relation suggests that the peak flux during the LH state that occurs at the beginning of an outburst is related to the mass in the disk, and thus that the entire disk is probably involved in powering these LH states. We have also found a positive correlation between the peak luminosities of the LH state in the three recent outbursts of GX 339-4 and the peak luminosities of the following HS state. This correlation is similar to the correlations reported previously for Aql X-1, 4U 1705À44, and XTE J1550À564, providing further support for the idea that the accretion flow that powers the LH state is related to the accretion flow that powers the following HS state. Although the luminosity of the LH-to-HS transition varies by up to an order of magnitude, the neutron stars and the black holes are distinguishable in the state transition luminosity. We discuss the implications for the mass determination of the compact stars in the ultraluminous X-ray sources (ULXs).

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Section: Correlation Between the Luminosity Of The Hard-to-softmentioning

confidence: 88%

Peak Luminosities of the Hard States of GX 339‐4: Implications for the Accretion Geometry, Disk Mass, and Black Hole Mass

Lamb

Fender

et al. 2007

ApJ

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“…Since then, monitoring campaigns using RXTE's pointed instruments, the Proportional Counter Array (PCA; Jahoda et al 1997) and the High Energy X-ray Timing Experiment, (HEXTE; Rothschild et al 1998), have been performed for virtually all known persistent and transient Galactic black hole candidates. Among many others, examples for such campaigns are those on LMC X-1 and LMC X-3 Wilms et al 2001), GX 339−4 Nowak et al , 2002Kong et al 2002;Homan et al 2005;Belloni et al 2005), V1408 Aql , 4U 1543−47 (Kalemci et al 2005), XTE J1650−500 (Kalemci et al 2003), 4U 1630−47 (Tomsick & Kaaret 2000), and XTE J1550−564 (Kalemci et al 2001;Sobczak et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Long term variability of Cygnus X-1

Wilms¹,

Nowak

Pottschmidt

et al. 2006

A&A

147

268

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Continuing the observational campaign initiated by our group, we present the long term spectral evolution of the Galactic black hole candidate Cygnus X-1 in the X-rays and at 15 GHz. We present ∼200 pointed observations taken between early 1999 and late 2004 with the Rossi X-ray Timing Explorer and the Ryle radio telescope. The X-ray spectra are remarkably well described by a simple broken power law spectrum with an exponential cutoff. Physically motivated Comptonization models, e.g., by Titarchuk (1994, ApJ, 434, 570, compTT) and by Coppi (1999, in High Energy Processes in Accreting Black Holes, ed. J. Poutanen, & R. Svensson (San Francisco: ASP), ASP Conf. Ser., 161, 375, eqpair), can reproduce this simplicity; however, the success of the phenomenological broken power law models cautions against "overparameterizing" the more physical models. Broken power law models reveal a significant linear correlation between the photon index of the lower energy power law and the hardening of the power law at ∼10 keV. This phenomenological soft/hard power law correlation is partly attributable to correlations of broad band continuum components, rather than being dominated by the weak hardness/reflection fraction correlation present in the Comptonization model. Specifically, the Comptonization models show that the bolometric flux of a soft excess (e.g., disk component) is strongly correlated with the compactness ratio of the Comptonizing medium, with L disk ∝ ( h / s ) −0.19 . Over the course of our campaign, Cyg X-1 transited several times into the soft state, and exhibited a large number of "failed state transitions". The fraction of the time spent in such low radio emission/soft X-ray spectral states has increased from ∼10% in 1996-2000 to ∼34% since early 2000. We find that radio flares typically occur during state transitions and failed state transitions (at h / s ∼ 3), and that there is a strong correlation between the 10-50 keV X-ray flux and the radio luminosity of the source. We demonstrate that rather than there being distinctly separated states, in contrast to the timing properties the spectrum of Cyg X-1 shows variations between extremes of properties, with clear cut examples of spectra at every intermediate point in the observed spectral correlations.

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“…Intermediate states are observed during transitions between the hard and the soft states and usually show the characteristic features of both (Miyamoto et al 1991;Mendez & van der Klis 1997;Kong et al 2002). For GX 339-4, Belloni et al (2005) Santo et al (2008).…”

Section: Introductionmentioning

confidence: 99%

Variability and Spectral Modeling of the Hard X-Ray Emission of Gx 339–4 in a Bright Low/Hard State

Droulans

Belmont

Malzac

et al. 2010

ApJ

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We study the high-energy emission of the Galactic black hole candidate GX 339−4 using INTEGRAL/SPI and simultaneous RXTE/PCA data. By the end of 2007 January, when it reached its peak luminosity in hard X-rays, the source was in a bright hard state. The SPectrometer on INTEGRAL (SPI) data from this period show a good signal-to-noise ratio, allowing a detailed study of the spectral energy distribution up to several hundred keV. As a main result, we report on the detection of a variable hard spectral feature ( 150 keV) which represents a significant excess with respect to the cutoff power-law shape of the spectrum. The SPI data suggest that the intensity of this feature is positively correlated with the 25-50 keV luminosity of the source and the associated variability timescale is shorter than 7 hr. The simultaneous Proportional Counter Array data, however, show no significant change in the spectral shape, indicating that the source is not undergoing a canonical state transition. We analyzed the broadband spectra in the lights of several physical models, assuming different heating mechanisms and properties of the Comptonizing plasma. For the first time, we performed quantitative model fitting with the new versatile Comptonization code belm, accounting self-consistently for the presence of a magnetic field. We show that a magnetized medium subject to pure non-thermal electron acceleration provides a framework for a physically consistent interpretation of the observed 4-500 keV emission. Moreover, we find that the spectral variability might be triggered by the variations of only one physical parameter, namely the magnetic field strength. Therefore, it appears that the magnetic field is likely to be a key parameter in the production of the Comptonized hard X-ray emission.

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Long-term X-ray variability and state transition of GX 339–4

Cited by 27 publications

References 58 publications

Peak Luminosities of the Hard States of GX 339‐4: Implications for the Accretion Geometry, Disk Mass, and Black Hole Mass

Peak Luminosities of the Hard States of GX 339‐4: Implications for the Accretion Geometry, Disk Mass, and Black Hole Mass

Long term variability of Cygnus X-1

Variability and Spectral Modeling of the Hard X-Ray Emission of Gx 339–4 in a Bright Low/Hard State

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